Polymers produced from 1,5-cyclooctadiene are well known in the art, and there are numerous processes which have been developed to produce such polymers. Most polymers and oligomers produced from 1,5-cyclooctadiene are rubbery. For example, British Pat. No. 977,931 describes a low temperature co-oligomerization of 1,5-cyclooctadiene and ethylene to produce amorphous elastomers which are vulcanizable. Additionally, German Pat. No. 2,438,915 (equivalent to U.S. Pat. No. 3,954,699) and Japanese Kokai Pat. No. 7,239,388 both describe a similar rubbery product produced from 1,5-cyclooctadiene and cyclopentene at temperatures from -10.degree. C. to 0.degree. C. using a tungsten chloride catalyst. Rubbery oligomers and polymers of this type appear to be of the ring-opened variety, as described by Sato et al., Macromolecular Chemistry, 178, 1993 (1977). These products result from use of metathesis catalysts such as vanadium, tungsten, or molybdenum which readily open cyclic compounds at carbon-carbon double bonds, reattaching the fragments to produce very large cyclic or acyclic materials.
It is also possible to prepare polymers from 1,5-cyclooctadiene which differ from the generally acyclic, rubbery polymers described above. For instance, Mondal and Young, Macromolecular Chemical Preparations, 1, 349 (1969), describe co-polymerization of 1,5-cyclooctadiene and styrene at temperatures of -20.degree. C. to 35.degree. C. using a titanium chloride or stannic chloride-water catalyst. Yan et al., Kexue Tongbao, 29, 1560 (1984), describe an aluminum chloride polymerization of 1,5-cyclooctadiene at similar low temperatures which produces a polymer having a molecular weight of 1,750. Still others have used a Ziegler catalyst made from titanium tetrachloride and triisobutyl aluminum to polymerize 1,5-cyclooctadiene and methyl-cyclootadiene, respectively. (see J. Polymer. Sci., Part A, 1, 2935 (1963) and J. Polymer. Sci., Part C, 16, 23 (1966)).
These non-rubbery polymers, whether produced using a Lewis acid catalyst or a Ziegler catalyst, both as described above, all involve a transannular product from the 1,5-cyclooctadiene, as shown below: ##STR1##
However, the products as produced by the prior art methods suffer from the drawback that they also contain high amounts of non-transannular impurities having the general formula: ##STR2## These non-transannular impurities have a marked effect on the polymer properties because the unused double bonds provide sites for side chain growth and cross-linking. These side chains and cross-linking sites caused by the high percentage of non-transannular impurity cause such polymers to be essentially globular and result in severely restricted compatabilities with polyethylene and polypropylene, and low solubilities in both aliphatic and aromatic organic solvents. It is thus desirable to obtain polymers produced from 1,5-cyclooctadiene which will have reduced levels of non-transannularity, which will exhibit high compatability with other hydrocarbon components, and which will have high softening points.